Antibiotics for the prevention and treatment of COVID-19: how effective are they?

The use of antibiotics made a huge breakthrough in the treatment of infectious diseases in the second half of the 20th century, thanks to them, mortality and disability from these diseases were significantly reduced. Dozens, and possibly hundreds of thousands of patients were saved, who were considered incurable before the invention of antibiotics. However, in the last couple of decades, humanity has faced such a problem as antibiotic resistance. Bacteria have learned to adapt to more and more new antibacterial drugs used against them, and have ceased to respond to them. In 2016, mathematicians in the United States built a predictive model for the development of antibiotic resistance, according to which it is assumed that in 2050 humanity will rapidly die from superinfection, which appeared due to resistant colonies of microorganisms. Despite the fact that new antibacterial drugs are constantly appearing, mainly due to the modification of existing classes, only 3 new classes of antibiotics have appeared in the last 30 years.

Current WHO data show that more than 50% of infections in Europe alone are caused by resistant microorganisms. And antimicrobial resistance genes have been found in microorganisms around the world. According to the CDC, in 2019 there were approximately 3 million cases of severe infections in the United States caused by bacteria that are not sensitive to any antibacterial drugs – of which 35 people could not be saved.

Scientists believe that the reason for the emergence of such resistance to antibiotics is the unreasonable and poorly controlled use of antimicrobials, for example, for the treatment of acute respiratory viral diseases (ARVI). And also an important role is played by the lack of bacteriological studies in the appointment of antibiotics, which allow identifying the pathogen and developing a treatment plan taking into account the flora and the sensitivity of antibiotics to it.

The new coronavirus infection is no exception, and today the problem of the unjustified prescription of antibiotics is more relevant than ever.

It must be clearly understood that the COVID-19 disease caused by SARS-Cov-2 is a viral disease, and it cannot be treated with antibiotics, since antibacterial drugs do not work on viruses.

Many people justify prescribing antibiotics by the presence of bilateral pneumonia (pneumonia). But this disease is of a viral nature, like the coronavirus, which means that antibiotics are not needed.

There are now clear indications for the use of antibiotics for COVID-19. These are complicated forms of infection, namely, when a secondary bacterial flora joins against the background of a viral one.

How to understand that a bacterial infection has joined?

The latest, 9th version of “Temporary guidelines for the prevention, diagnosis and treatment of a new coronavirus infection COVID-19 dated 26.10.2020/0,5/10.” states: “Antibacterial therapy is prescribed if there are convincing signs of a bacterial infection (an increase in procalcitonin more than 109 ng / ml, leukocytosis> XNUMX * XNUMX / l, the appearance of purulent sputum.” Indirect signs of the addition of a secondary bacterial flora and the occurrence of bacterial pneumonia can serve as wet wheezing heard locally on auscultation recurrence of temperature after normalization The decision to prescribe antibiotics should be made only by a doctor There are certain changes in the tests that may indicate a worsening of the patient’s condition and a worse prognosis.

• D-dimer: increase above 1000 ng / ml (norm up to 500);
• C-reactive protein (CRP or CRP): increase above 100 (normal up to 8);
• LDH: increase above 245 (normal 110-210 unit/L);
• troponin: more than 2 times the upper limit of normal;
• ferritin: increase above 500;
• CPK: more than 2 times higher than the upper limit of normal;
• thrombocytopenia (decrease in the number of platelets), lymphopenia (decrease in absolute units of the number of lymphocytes).

But you need to clearly understand that it does not always make sense to focus on CRP, ferritin, and other laboratory markers of inflammation as signs of a secondary bacterial infection in patients with COVID-19, since their increase is often due to the development of a hyperimmune response, and cannot be a reason for prescribing antibiotics.

The only reliable laboratory marker that allows differentiating a bacterial and hyperimmune process in a patient with COVID-19 is the level of procalcitonin in the blood, namely its increase.

Unlike conventional bacterial pneumonias, COVID-19 lung damage and changes caused by this damage may be associated with immune mechanisms when the so-called “cytokine storm” develops due to macrophage activation syndrome. And with such a mechanism of changes in the lungs, antibacterial drugs are absolutely ineffective. There is now active discussion about the use of the term “viral interstitial lung disease”, “viral pneumonia” or “viral pneumonitis” instead of the term “pneumonia” for lung damage caused by SARS-Cov-2. These terms more realistically reflect the pathogenetic mechanism of the development of processes in COVID-19, and also give practical doctors involved in the treatment of such pneumonia not to prescribe antibiotics at the initial stage of the disease without the above-mentioned reliable signs of a bacterial infection. Unfortunately, it is doctors who now also began to prescribe antibiotics in the early stages of the disease, and sometimes even to asymptomatic positive carriers of the virus. This is justified by the desire to avoid complications and prevent their occurrence. In addition, the fact that at the beginning of the appearance of COVID-19, doctors did not know how to treat a new infection, and used various drugs, including antibiotics, to influence the virus, also plays a role. However, clinical data accumulated over several months, as well as ongoing studies, suggest that the use of any antibacterial drugs at an early stage of the development of the disease, as well as for the purpose of prevention, does not improve the prognosis of the course of the disease, does not affect the severity of the disease and mortality.

On October 17, 2020, a joint appeal was issued to the Russian medical community from:

• Interregional Association of Respiratory Medicine Specialists;
• Alliance of Clinical Chemotherapists and Microbiologists;
• Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy;
• Russian Respiratory Society;
• Pediatric Respiratory Society;
• Association of Children’s Doctors of the Moscow Region.

It reads: “We call on practitioners and heads of medical organizations providing care to patients with a new coronavirus infection COVID-19 to refuse unreasonable prescription of antibiotics, especially in a hospital setting where there is a possibility of laboratory confirmation of a bacterial infection, and to comply with the provisions set out in the current version Temporary guidelines “Prevention, diagnosis and treatment of a new coronavirus infection (COVID-19) of the Ministry of Health of Russia (version 9.1 of 26.10.2020/XNUMX/XNUMX), regarding the use of antibiotic therapy”.

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